In the related art, there is known a biometric authentication technology that performs authentication using biometric information such as a fingerprint or the like. An authentication device that performs biometric authentication retains data generated based on biometric information as registration data. When data to be matched is input, the authentication device matches the input data and registration data and determines success or failure of authentication, based on degree of similarity between the input data and the registration data.
In such a biometric authentication technology, since biometric information of a user varies with time elapse, an authentication rate may be decreased. Therefore, in recent years, there has been proposed an authentication device that updates registration data with input data received from a user when authentication succeeds. In the case of using such an authentication device, since the registration data is updated with latest data, an authentication rate may be improved.    Patent Literature 1: Japanese Laid-open Patent Publication No. 2008-102770